Commit 65a8fc30 authored by Bernard Metzler's avatar Bernard Metzler Committed by Leon Romanovsky
Browse files

RDMA/siw: Fix user page pinning accounting 



To avoid racing with other user memory reservations, immediately
account full amount of pages to be pinned.

Fixes: 2251334d ("rdma/siw: application buffer management")
Reported-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Suggested-by: default avatarAlistair Popple <apopple@nvidia.com>
Reviewed-by: default avatarAlistair Popple <apopple@nvidia.com>
Signed-off-by: default avatarBernard Metzler <bmt@zurich.ibm.com>
Link: https://lore.kernel.org/r/20230202101000.402990-1-bmt@zurich.ibm.com


Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
parent ef425202

drivers/infiniband/sw/siw/siw_mem.c

+12 −11
Original line number Diff line number Diff line
@@ -398,7 +398,7 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable) 


	mlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;



	if (num_pages + atomic64_read(&mm_s->pinned_vm) > mlock_limit) {

	if (atomic64_add_return(num_pages, &mm_s->pinned_vm) > mlock_limit) {

		rv = -ENOMEM;

		goto out_sem_up;

	}
@@ -411,30 +411,27 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable) 
		goto out_sem_up;

	}

	for (i = 0; num_pages; i++) {

		int got, nents = min_t(int, num_pages, PAGES_PER_CHUNK);



		umem->page_chunk[i].plist =

		int nents = min_t(int, num_pages, PAGES_PER_CHUNK);

		struct page **plist =

			kcalloc(nents, sizeof(struct page *), GFP_KERNEL);

		if (!umem->page_chunk[i].plist) {



		if (!plist) {

			rv = -ENOMEM;

			goto out_sem_up;

		}

		got = 0;

		umem->page_chunk[i].plist = plist;

		while (nents) {

			struct page **plist = &umem->page_chunk[i].plist[got];



			rv = pin_user_pages(first_page_va, nents, foll_flags,

					    plist, NULL);

			if (rv < 0)

				goto out_sem_up;



			umem->num_pages += rv;

			atomic64_add(rv, &mm_s->pinned_vm);

			first_page_va += rv * PAGE_SIZE;

			plist += rv;

			nents -= rv;

			got += rv;

			num_pages -= rv;

		}

		num_pages -= got;

	}

out_sem_up:

	mmap_read_unlock(mm_s);
@@ -442,6 +439,10 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable) 
	if (rv > 0)

		return umem;



	/* Adjust accounting for pages not pinned */

	if (num_pages)

		atomic64_sub(num_pages, &mm_s->pinned_vm);



	siw_umem_release(umem, false);



	return ERR_PTR(rv);